Oil and gas well cleaning apparatus



Aug. 29, 1961 R. CASADY ET AL 011. AND GAS WELL CLEANING APPARATUS 2 Sheets-Sheet 1 Filed Aug. 11, 1959 m H M m mam m a. .0 W 4 V. w z 4% Wu Z Aug. 29, 1961 R. L. CASADY ET AL 2,998,074

OIL AND GAS WELL CLEANING APPARATUS Filed Aug. 11, 1959 2 Sheets-Sheet 2 United States Patent O "ice 2,298,074 OIL AND GASWELL CLEANING APPARATUS Richard L. Casady and James D. Mooneyham, Liberal,

Kans., assignors to Camo Tool Company, Inc., a corporation of Kansas Filed Aug. 11, 1959, Ser. No. 833,104 7 Claims. (Cl. 166-172) This invention relates to the general class of earth boring tools and, more specifically, the instant invention pertains to boring apparatus primarily adapted for use in oil or gas wells to enlarge the bore opposite the oil or gas bearing stratus and to clean foreign matter from the inner surfaces of. the wells.

One of the primary objects of. this invention is to provide a boring or cleaning device for oil and gas wells having open formation which lends itself. to rapid and eflicient removal of foreign deposits on the inner wall of, the well, to increase the flow of the gas or oil and thereby to increase the production thereof.

As is well known to those in the practice of this art,

the surface of the cavity wall of an oil or gas well frequently becomes practically impervious to the oil or gas contained in the adjacent. oil or gas bearing stratum. Thissealed condition of. the wall of the well is usually caused by the coating thereof with fine sand, paraffin, asphaltum or other compositions all depending upon the nature of the stratum formation. This, of course, results in the-reduction.- in the productivity of the wall and, in accordance with some practices, frequently requires that the well be shot. Such attempts to alle- -viate or remove this internal coating is not generally successful inasmuch "as the force-of the explosion causes the pores of the gas or oil bearing stratum to: become clogged with the very materials sought to be dispersed. Thus, it is another object of. this=-invention. to provide a well cleaning tool which lends itself to the rapid and efiicient removal. of such foreign deposits as may accumulate on the inner wall of. a gas. or oil well regardless of the nature thereof.

It is a further object of this invention to provide well cleaning apparatus which is positivev in operation and which. may be readily inserted. into and withdrawn from the well.

This invention has, as a. stillv further object thereof,

the provision of gas and oil. well: cleaning apparatus including a plurality of cleaning blades which are ex- -construction and assembly, inexpensiveto manufacture and durable in use.

Other and further objectsand advantages of the instant. invention will become more evident from a consideration of the following specification when read. in

conjunction with the annexed drawings, in'which:

FIGURE 1 is a side elevational view' of gas and oil well cleaning apparatus constructed in accordance with this invention, FIGURE 1 illustrating the blades of the apparatus expanded to their operative positions within a gas or oil well;

FIGURE 2 is a side elevational view of the gas" or oil well cleaning apparatus shown in. FIGURE 1, FIG- Patented Aug. 29, 1961 URE 2 illustrating the, apparatus with the blades thereof retracted to their inoperative positions;

FIGURE 3 is a bottom plan viewof the apparatus illustrated in FIGURE 1, FIGURE 3 also showing the cleaning blades in their expanded positions;

FIGURE 4 is an enlarged fragmentary detail cfoss sectional view of the gas or oil well cleaning. apparatus, FIGURE 4 being taken substantially on the vertical plane of line 4--4 of FIGURE 2, looking in the direction of the arrows;

FIGURE 5 is. a detail cross-sectional View taken substantially on the horizontal plane of line 5--5 of FIG- URE 4, looking in the direction of the arrows;

FIGURE 6 is a detail cross-sectional view, FIGURE 6 being taken substantially on the horizontal plane of line 6-6 of FIGURE 4, looking in the direction of the arrows;

FIGURE 7 is-a detail cross-sectional view, FIGURE 7 being taken substantially on the horizontal plane of line 7-7 of FIGURE 4, looking inthe direction of the arrows; and,

FIGURE 8 is an exploded perspective. view of one of the cleaning blade assemblies.

Referring now more specifically to the drawings, refe erence numeral 10 designates, in general, oil or gas well cleaning apparatus constructed in accordance with. the teachings of this invention. As disclosed, the apparatus 10 includes a basic unit indicated at A and one or. more secondary or intermediate units B, only one: of the latter being shown to eliminate needless repetition.-

The unit A is seen to comprise. an elongated length of hollow cylindrical tubing 12 internally threaded adjacent its. opposed upper and lower ends. The tubing 12, intermediate the ends thereof, is formed with a pluralityof circumferentially spaced, axially extending, elongated substantially rectangular slots. 14.

Threaded into the lower end of the tubing 12 is an inverted. substantially hollow, elongated, ogive-shaped .pushrod guide 16. truncated at the apexend 18' thereof.

To serve functions to be described infra, the push rod guide 16, is. formed with a plurality of circumferentially spaced, transversely extending, and downwardly opening passages 20-, and an axially extending bore 22. The guide. 16 and the tubing 14 together with its associated component elements are mounted for reciprocation. on a push rod 24 which extends through the bore 22, into and beyond the upper end of the tubing 12 andis coaxial with respect thereto. The lower end of the push rod 24 terminates in an enlarged ground engaging abutment head 26, and adjacent the truncated end ofthe guide 16 the push rod 24.. is formed with a plurality of axially spaced diametrically extending passages 28 adapted. to selectively receive a shear pin 30 therethrough. As isv seenin the drawings, a substantially solid cylindrical disc 32 is constructed with a centrally positioned bore. 34 extending transversely therethrough to slidably receive a portion of said push rod 24. To serve a function to be described, the disc 32 is also provided with a plurality of circumferentially sp'aced substantially rectangular cutting blade guide passages 36 which open into the plane of the upper side of the disc 32 adjacent. the circumferential marginal edge thereof and extend downwardly at an acute angle with respect to the'longitudinal axis of. the: push. rod 24 to open into the plane. ofthe lower side of the disc 32 intermediate the side 38 and the. bore 34. Superimposed on the upper side of the. disc 32 is a cylindrical stop collar 40 having a central bore 42 extending therethrough in which is received the push rod 24. The collar 40 is releasably secured to. the push rod 24 by a set screw 44. Reference numeral 46 denotes one of a plurality of elongated substantially rectangular cutting blades 46 other.

formed of a flexible resilient material such as, for ex-- ample, spring steel, and each cutting blade includes an elongated bight portion 48 having integrally connected to the lower end thereof a laterally ofiset arm 50 which s loosely received within, respectively, the blade guide passages 36 and extend at an acute angle with respect to the longitudinal axis of the push rod 24. The outer ends of each of the arms 50 terminate in tongues 52 bent inwardly towards the push rod 24. As is clearly shown in FIGURE 4, each of the arms 50 are apertured adjacent its tongue 52 and receive therethrough a stop bolt 54 secured thereon by a nut 56. The stop bolts 54 serve to prevent the upward withdrawal of the blades 46 through the passages 36.

The upper ends of the bights 48 of the blades-46 are integral with arms 58 laterally ofiset from the former in the opposite direction with respect to annsSO and are inclined. towards the axis of the push rod 24 at an acute angle. The upper ends of the arms 58 are bent substantially parallel to the axis of the push rod 24 and are apertured at 60 to serve in a manner to be described. The outer upper ends of the arms 58 terminate' in inwardly projecting tongues 62 which are also inclined at an acute angle with respect to the axis of the push rod 24;

The tubing 12 adjacent its upper end is formed with a plurality of tapped circumferentially spaced openings :which threadedly receive the externally threaded heads 64 of a plurality of bolts having smooth shanks 66, the latter loosely traversing the apertures 60 and extend into cylindrical sockets 68 which radiate at circumferentially spaced intervals in asecond disc 70 having a chamfered j-upper peripheral side 72 adapted to seat against the inner sides of the tongues 62.

- The unit B is similar in construction with respect to theunit A with but few exceptions, and to avoid needless iteration, elements thereof having counterparts in the-unit A have been assigned the same reference numerals to which a prime mark has been added to dilferentiate one from the other. 7

As is illustrated clearly in FIGURE 4, the lower end of the tubing 12' instead of receiving an ogive-shaped push rod guide, is necked down to form an axially externally threaded extension 72 that is threadedly connected to the internally threaded upper end of the tubing 12; In all otherrespects the two units A and B are identical;

(It should be here noted that while the drawings illus- -trate the use of only one of the units B, it is to beunderwith a longitudinally extending substantially rectangular bolt receiving slot 78. The scraper 74, substantially centrally of the ends thereof, is provided with a second "bolt hole 80. A plurality of bolts 84 (see FIGURE 1) extend through the bolt holes 76, 78 and 80 and are selectively engaged within any sequential series of bolt holes 86 formed in the blade 46, the bolt holes 86 being disposed in longitudinally spaced relation relative to each Each 'of the plates74 are formed with zigzag raised roughened ribs 87 to abrade the side of the well.

To utilize the apparatus described immediately above,

the upper end of the tubing -12' is fixedly connected to a collar 88 which is, in turn, threadedly connected with the lower end of a swedge' 90 having an externally threaded upwardly projecting neck 92. Reference numeral 94 denotes an elongated substantially hollow tubularmember formed with a plurality of fluid outlet perforations 96, the element 94 being known in the art as a pup joint or fishing neck. The lower end of the pup joint 94 is connected to the neck 92 by means of a conventional coupler member 98.

The pup joint 94 is constructed in a conventional manner with a one-way check valve at the lower end thereof (not shown) and the upper end of the pup joint 94 is threadedly connected to the lower end of a drill string (not shown) which is, in turn, connected with a source of drilling fluid under pressure. Conventional means are also provided and areshown herein for efiecting the rotation of the drill string and consequently of the two tubing members 12, 12'.

The well cleaning and scraping apparatus 10 is adapted to be lowered through a well casing to a point below the lower end thereof, the blades, while this operation is being carried out, being disposed in their retracted positions as is illustrated in FIGURES- 2 and 4 of the drawings. 7 To retract the cutting blades from their extended positions as is illustrated in-FIGURE 1 to their retracted positions of FIGURES 2 and 4, the push rod V therethrough. The tension of the blades 46 is such as to cause the shear pin 30 to engage tightly against the truncated end 18 upon release of the push rod 24. In moving the push rod 24 downwardly, the collar 40 exerts a pressure on the upper side of the disc 32 causing the same to move downwardly relative to the tubing 1-2 until the push rod 24 is locked against movement in the manner described above.

After the apparatus 10 passes below the lower end of the well casing it enters-the gas or oil well bearing stratum 100, and the enlarged abutment head 26 is caused to em gage against the bottom of the well 102 (see FIGURE 1); The weight of the apparatus 10 plus the weight of the drill stem (not shown) is sufiiciently great to cause the units A, B to move downwardly and axially with re, spect to the push rod 24 and shears the pin 30. After the pin 18 has been sheared continued downward movement of the tubing 12, 12' causes the blades 46 to bow outwardly and to project beyond the slots 14.

It should be here observed-that when the disc 32 has been moved downwardly to its lowermost position and secured therein by means of the shear pin 30, the disc 32' has also been moved downwardly under the force exerted by the collar 40' which is also secured to the push rod 24. Thus the shear pin 30 holds the rod 24 stationary with both sets of blades 48. 48' disposed in their retracted position. At the same time. and upon shearing of the pin 30, both sets of blades 48, 48' are caused to expand through their respective slots in the manner described above.

When the blades 48, 48' have been released, fluid is transmitted through the drill stem and is sprayed through the pup joint and fishing neck 94% wash the face of the gas or oil bearing stratum. The tubing 48, 48' being rotatably driven causes the blades 48 and the scraper blades 74 to cut and abrade the side wall of the well thereby freeing the same of its accumulated hardened debris and restoring the normal flow of the gas and/or ,oil.

Upon completion of the cleaning operation the tubin 12, 12' is drawn through the well casing together with the drill string in the conventional manner.

Having described and'illustrated one embodiment of this invention, it is to be understood that the same is offered merely by way of example, and that this invention is to be limited only by the scope of the appended claims.

What is claimed is:

1. A tool of the character described comprising an elongated cylindrical tube having an open upper end and a closed lower end, means on said upper end for connecting said tube with rotating means, an elongated push rod mounted for reciprocation through said lower end. said push rod having a portion disposed internally of said U t lhe and a lower end portion extending below said-closed end, a disc. mounted for free reciprocation on said push rod adjacent said closed end and being free to reciprocate said tube, a collar fixedly secured to said push rod and normally engaging the upper side of said disc, said having a plurality of guide passages extending vertically therethrough, said passages being angled inwardly toward said closed end at acute angles relative to the axis of the push rod, the side wall of said tube havmg a plurality of longitudinal slots therein, an arouately shaped spring blade disposed in each of said slots, said blades having main portions normally extending beyond the exterior of the tube, said blades having lower ends extending through said guide passages, means on said lower ends engaging the lower side of said disc to prevent upward withdrawal from said guide slots, a second disc having a bore slidably receiving said push nod, said second disc being disposed adjacent said upper end of the tube, said blades having upper ends connected with said second disc, said closed lower end having a plurality of passages extending therethrough for passing material cut by said blades into the tube.

2. A tool of the character described comprising an elongated cylindrical tube having an open upper end and a. closed lower end, means on said upper end for connecting said tube with rotating means, an elongated push rod mounted for reciprocation through said lower end, said push rod having a portion disposed internally or said tube and a lower end portion extending below said closed end, a disc mounted for free reciprocation on said push rod adjacent said closed end and being free to reciprocate within said tube, a collar fixedly secured to said push rod and normally engaging the upper side of said disc, said disc having a plurality of guide passages extending vertically therethrough, said passages being angled inwardly toward said closed end at acute angles relative to the axis of the push rod, the side wall of said tube having a plurality of longitudinal slots therein, an arcuately shaped spring blade disposed in each of said slots, said blades having main portions normally extending beyond the exterior of the tube, said blades having lower ends extending through said guide passages, means on said lower ends engaging the lower side of said disc to prevent upward withdrawal from said guide slots, a second disc having a bore slidably receiving said push rod, said second disc being disposed adjacent said upper end of the tube, said blades having upper ends connected with said second disc, said closed lower end having a plurality of passages extending therethrough for passing material cut by said blades into the tube, said closed end of the tube comprising a substantially hollow downwardly tapered guide having a central bore receiving said push rod.

3. A tool of the character described comprising an elongated cylindrical tube having an open upper end and a closed lower end, means on said upper end for connecting said tube with rotating means, an elongated push rod mounted for reciprocation through said lower end, said push rod having a portion disposed interially of said tube and lower end portion extending below said closed end, a disc mounted for free reciprocation on said push rod adjacent said closed end and being free to recipnocate within said tube, a collar fixedly secured to said push rod and normally engaging the upper side of said disc, said disc having a plurality of guide passages extending vertically therethrough, said passages being angled inwardly toward said closed end at acute angles relative to the axis of the push rod, the side wall of said tube having a plurality of longitudinal slots therein, an arcuately shaped spring blade disposed in each of said slots, said blades having main portions normally extending beyond the exterior of the tube, said blades havin lower ends extending through said guide passages, means on said lower ends engaging the lower side of said disc to prevent upward withdrawal from said guide slots, a second disc having a bore slidably receiving said push an elongated well bottom engaging head.

rod, said .second disc being disposedadiaeent said upper end of the tube, said blades having upper ends. connected with said second disc, said closed lower end having a plurality of passages extending therethroughior passing ma;- terial out by said blades into the tube, said closed end of the tube comprising a substantially hollow downwardly tapered guide having a central bore receiving said push rod, the'lower end of .said push rod being provided with 4. A tool of the character described comprisingatube having open upper and lower ends,1means on said upper end for connection to rotating means, an upper disc disposed in said tube adjacent to and spaced from the upper end and secured to said tube, a lower disc mounted slidablytin the tube at the lower end of the tube, said discs having axial openings, a push rod axially mounted in the tube and extending through the disc openings for endwise reciprocation, said rod having a lower end portion extending below the lower end of the tube and terminating in a well bottom engaging head, the side wall of the tube being formed with circumferentially spaced closed vertical slots, outwardly bowed resilient "blades having main portions normally extending out through said slots, said blades having upper end portions fixed to the upper disc and lower end portions secured to the lower disc for limited vertical movement relative to the lower disc, and

stop means on the push rod immediately above the lower disc, a hollow rod guide secured on the lower end of the tube, said rod guide having a perforated side wall and a lower end formed with an axial bore slidably receiving the push rod.

5. A tool of the character described comprising a tube having open upper and lower ends, means on said upper end for connection to rotating means, an upper disc disposed in said tube adjacent to and spaced from the upper end and secured to said tube, a lower disc mounted slidably in the tube at the lower end of the tube, said discs having axial openings, a push rod axially mounted in the tube and extending through the disc openings for endwise reciprocation, said rod having a lower end portion extending below the lower end of the tube and terminating in a well bottom engaging head, the side wall of the tube being formed with circumferentially spaced closed vertical slots, outwardly bowed resilient blades having main portions normally extending out through said slots, said blades having upper end portions fixed to the upper disc and lower end portions secured to the lower disc for limited vertical movement relative to the lower disc, and stop means on the push rod immediately above the lower disc, a hollow rod guide secured on the lower end of the tube, said rod guide having a perforated side wall and a lower end formed with an axial bore slidably receiving the push rod, said lower end portion of the push rod having vertically spaced transverse bores therethrough, and a shear pin engaged in a selected transverse bore and bearing against the lower end of the slot guide with the blades in elongated condition wherein the main portions of the blades are retracted into said slots.

6. A tool of the character described comprising a tube having open upper and lower ends, means on said upper end for connection to rotating means, an upper disc disposed in said tube adjacent to and spaced from the upper end and secured to said tube, a lower disc mounted slid ably in the tube at the lower end of the tube, said discs having axial openings, a push rod axially mounted in the tube and extending through the disc openings for endwise reciprocation, said rod having a lower end portion extending below the lower end of the tube and terminating in a well bottom engaging head, the side wall of the tube being formed with circumferentially spaced closed vertical slots, outwardly bowed resilient blades having main portions normally extending out through said slots, said blades having upper end portions fixed to the upper disc and lower end portions secured to thelowerrdisc vfor limitedvertical movement relative 7. A tool of the characterdescribed comprising lower and upper sections, said sections comprising tubes having upper and lower ends, means reciprocably connecting the lower end of the upper tube to the upper end of the lower tu be, upper discs disposed in said tubes adjacent to and spaced from the upper ends of said tubes and secured to said tubes, lower discs slidably mounted in the tubes at their lower ends, said discs having aligned axial openings therethrough, a push rod extending slidably through the disc openings, said rod having a lower end portion extending below the lower end of the lower tube and terminating in a well'bottorn engaging head, stops fixed on the rod immediately above the lower discs, the sidewalls of the tubes having there'through circumferentially spaced closed vertical slots, outwardly bowed resilient blades having main portions positioned in and normally expanded outwardly through the slots, said blades having upper end portions secured to the upper discs and lower end portions securably and slidably engaged with the lower discs, said upper discs having peripheral edges spaced from the tube sidewallspand a hollow rod guide secured on the lower end of the lower tube, said rod guide having openings in its sidewall communicating-with the interior of the lower tube, said rod guide having a lower end formed with an axial bore through which th push rod slides.

References Cited in the file of this patent UNITED STATES PATENTS Watrous Dec. 7, 1880 235,319 I 1,402,503 Krause Jan. 3, 1922 1,402,786 Muehl June 10, 1922 1,764,373 vWells et a1 June-17, 1930 1,823,367 Lorenz Sept. 15, 1931 2,296,514

Gibson Sept. 22, 1 9,42 

